SOME GENERAL CHARACTERS OE SALIVA. 
5oi 
Interval 
bi 1 ween each 
Period of Col- 
lection and the 
one before it. 
2 minutes 
H „ 
20 
2 
13 
3 
1 
Amount of 
Saliva in c.c. 
3-5 
3-5 
3-0 
2-S 
3-0 
3-0 
2-5 
3-1 
2-8 
Kate of Secre- 
tion in c.c. per 
Minute. 
Percentage 
of 
Organic 
Substance. 
0-14 
0-52 
0-87 
1-54 
0-66 
1-63 
o-ii 
1-07 
TOO 
0-91 
0-50 
0-76 
0-13 
0-48 
077 
0-51 
0-31 
0-42 
Percentage 
of 
Suits. 
•22 
•56 
■45 
•36 
■49 
•39 
■30 
•38 
•36 
Total 
Percentage 
of 
Solids. 
074 
2-10 
2-08 
1-44 
1-41 
1-16 
0-78 
0-90 
0-79 
Some General Characters of Saliva, and its Microscopic 
Constituents. 
The viscidity of saliva, secreted by mucous glands, is generally in 
proportion to the percentage of mucin which it contains. This, of 
course, would not be the case, if the amount of alkaline salt in the 
saliva increased in much larger proportion than the amount of mucin, 
for, with a given quantity of mucin, the viscidity of the fluid varies with 
the amount of the solvent. 
Saliva, from albuminous or from mixed glands, may be either watery 
or thick, irrespective, within certain limits, of the percentage of organic 
substance present. Sublingual saliva and parotid saliva of the dog, 
when they have a high percentage of organic substance, have a tendency 
to turn into a jelly-like mass, and this may further separate into a clot 
and clear fluid. 
In very watery saliva, freshly secreted, which has not been allowed 
to stand in the ducts, and which is examined without delay, nothing is 
to be seen under the microscope. 
When saliva is allowed to stand a short time in the ducts, car- 
bonic acid is given off from it, and, in consequence, calcium carbonate 
is precipitated ; the precipitate renders the saliva cloudy, and under 
the microscope appears as very fine particles, or groups of particles. 
On irrigating such a specimen with dilute mineral acid, the particles 
are dissolved. The saliva also may contain leucocytes, and will certainly 
do so if it has been allowed to stay long in the gland ducts. In ordinary 
experimental conditions, leucocytes collect in the connective tissue of 
the glands, and migrate, at times in large numbers, into the ducts. The 
leucocytes at first show amoeboid movement ; later, they swell, become 
vacuolated, and form the bodies which have been called salivary cor- 
puscles. The saliva may also contain some cells from the ducts 
which have been separated or injured by insertion of the cannula, 
some isolated nuclei, either of duct cells or of leucocytes, and occasionally 
a few small fat globules. 
